Printing colored contact lenses

ABSTRACT

A method of making a colored contact lens comprises printing at least one layer of a colorant onto a contact lens using a printing process selected from the group consisting of ink jet printing, electrophotographic printing, thermal transfer printing, and photographic development printing. Printing can be done directly on the contact lens, on a film in a mold where the contact lens is formed, or on a cliché pad. Multiple layers of colorants can be printed onto a contact lens.

[0001] This application claims under 35 U.S.C. § 119(e) the benefit ofthe filing date of U.S. Provisional Patent Application Serial No.60/213,217 filed Jun. 20, 2000 and of U.S. Provisional PatentApplication Serial No. 60/211,024 filed Jun. 12, 2000.

BACKGROUND

[0002] For cosmetic purposes, contact lenses having one or morecolorants dispersed in the lens or printed on the lens are in highdemand. These colored contact lenses enhance the natural beauty of theeye, or provide unique patterns on the iris of the wearer.

[0003] Presently, methods of printing inks onto contact lenses involvecliché ink transfer printing. A typical example of this printingfollows. An image is etched into metal to form a cliché. The cliché isplaced on a printer. Once on the printer, the cliché is inked by eitheran open inkwell doctoring system or by a closed ink cup sliding acrossthe image. Then, a silicone pad picks up the inked image from the clichéand transfers the image to the contact lens. The silicone pads are madeof a material comprising silicon that can vary in elasticity. Theproperties of the silicone material permit the inks to stick to the padtemporarily and fully release from the pad when it contacts the contactlens.

[0004] There are several disadvantages associated with using cliché inktransfer printing to color contact lenses. This method lacksconsistency. Slight differences in the silicone pad can cause widevariation in image quality, effecting dot resolution and colorreproducibility. Further, multiple color layering is difficult and timeconsuming. Further still, the design and printing process using thismethod is slow. After an image is fully designed, it can take about twoweeks before that image is etched onto a cliché. The set-up ispainstakingly detailed and lengthy when more than one color is going tobe printed on the lens using this method. Presently, only three overlaysof color can be applied using this printing method. The difficulty andslowness of this printing method inhibits business strategies, making itdifficult to offer consumers a chance to design and print their owncontact lenses at the point of purchase.

[0005] A printing apparatus and printing method are needed that canproduce high quality images in a consistent manner on contact lenses. Asimple, quick, and highly precise printing apparatus and method areneeded when multiple colors are being printed onto a contact lens,preferably one that permits consumers to design and print their owncontact lenses when they purchase those lenses.

SUMMARY OF THE INVENTION

[0006] The products and processes of the present invention address atleast some of the difficulties in the prior art.

[0007] In one aspect of the invention, a method of making a coloredcontact lens comprises printing at least one layer of a colorant onto acontact lens using a printing process selected from the group consistingof ink jet printing, electrophotographic printing, thermal transferprinting, and photographic development printing.

[0008] In another aspect of the invention, a method of making a coloredcontact lens comprises: (a) printing a first layer of a colorant in afirst pattern onto a contact lens using a printing process selected fromthe group consisting of ink jet printing, electrophotographic printing,thermal transfer printing, and photographic development printing; (b)printing at least one second layer of a colorant in a second patternonto a contact lens using a printing process selected from the groupconsisting of ink jet printing, electrophotographic printing, thermaltransfer printing, and photographic development printing; and (c)coating the colored contact lens with a binding solution comprising amonomer or a polymer.

[0009] In still another aspect of the invention, an improved method ofmaking colored contact lenses comprises printing at least one layer of acolorant onto a contact lens using a printing process selected from thegroup consisting of ink jet printing, electrophotographic printing,thermal transfer printing, and photographic development printing.

[0010] The present invention provides the foregoing and other features,and the advantages of the invention will become further apparent fromthe following detailed description of the presently preferredembodiments, read in conjunction with the accompanying figures. Thedetailed description and figures are merely illustrative of theinvention and do not limit the scope of the invention, which is definedby the appended claims and equivalents thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 shows electrophotographic printing onto contact lensesusing a photosensitive sphere.

[0012]FIG. 2 shows electrophotographic printing onto contact lensesusing a photosensitive hemisphere.

[0013]FIG. 3 shows thermal transfer printing onto contact lenses.

[0014]FIG. 4 shows a top view of the thermal transfer printing of FIG.3.

[0015]FIG. 5 shows a cross section of the lens in FIG. 3 after it hasbeen printed on using thermal transfer printing.

[0016]FIG. 6 shows photographic transfer printing onto contact lenses.

[0017]FIG. 7 shows an image printed onto a contact lens by photographictransfer printing.

DETAILED DESCRIPTION DEFINITIONS

[0018] “Colorant” means either a dye or a pigment or a mixture thereof.

[0019] “Dye” means a substance that is soluble in a solvent and that isused to impart color. Dyes are typically translucent and absorb but donot scatter light. Dyes can cover both optical regions of contact lensesand non-optical regions of contact lenses.

[0020] “Fluorescence” means luminescence caused by absorption of visiblelight or ultraviolet radiation at one wavelength followed by nearlyimmediate emission at a longer wavelength. Fluorescent emission ceasesalmost immediately when the light or incident ultraviolet radiationstops.

[0021] “Monomer” means low molecular weight compounds that can bepolymerized. Low molecular weight typically means average molecularweights less than 700 Daltons. The term “monomer” also refers to mediumand high molecular weight compounds or polymers, sometimes referred toas macromonomers, (that is, typically having number average molecularweights greater than 700) containing functional groups capable offurther polymerization.

[0022] “Pearlescence” means having a pearly luster; resembling a pearlin physical appearance; or having a nearly neutral slightly bluishmedium gray color.

[0023] “Phosphorescence” is luminescence caused by the absorption ofradiation at one wavelength followed by delayed emission at a differentwavelength. Phosphorescent emission continues for a prolonged time afterthe incident radiation stops.

[0024] “Pigment” means a powdered substance that is suspended in aliquid in which it is relatively insoluble. Pigments are used to impartcolor. Because pigments are in the form of a suspension, they tend tohave an opacity quality. That is, they reflect light and obstruct thepassage of light. For this reason, it is preferred that pigments arelocated in non-optical regions of a contact lens.

[0025] “Polymer” means a material formed by polymerizing one or moremonomers.

THE CONTACT LENSES

[0026] The methods of the present invention involve printing a colorantonto a contact lens using ink jet printing, electrophotographicprinting, thermal transfer, or photographic development. The image ispreferably a digital image, but it can also be an analog image.

[0027] In one embodiment, the contact lenses are transparent before theyare printed upon. In another embodiment, the contact lenses are tintedprior to being printed upon. That is, a colorant may have been dispersedin that lens using methods that are well known in the art before thatlens is printed upon using digital technology.

[0028] In another embodiment, the contact lenses that are going to beprinted upon can optionally have been pre-printed using methods that arewell known in the art. The well known methods include the ones disclosedin U.S. Pat. No. 5,116,112, which is hereby incorporated by reference.This method involves coating a colored liquid (which is eitherthermosetting or thermoplastic) in a mold for making a contact lens ontoa surface thereof where the iris portion of the lens is formed toproduce a colored film providing a pattern thereon which film contains asurface exposed to the interior of the mold and a surface in contactwith the mold; and charging the mold with the lens-forming liquid usedto form the body of the lens while maintaining the colored film in theiris portion and configuring the lens-forming liquid about the coloredfilm whereby the surface of the film becomes integral with the body ofthe lens and surface of the film becomes part of the outer surface ofthe lens when the molded lens is removed from the mold.

INK JET PRINTING

[0029] Preferably, the colorant applied to the contact lens using an inkjet printer is an ink. A preferred ink contains at least one dye. Nearlyany dye can be used in the present invention, so long as it can be usedin an ink jet printer. These dyes include fluorescent dyes,phosphorescent dyes, pearlescent dyes, and conventional dyes.

[0030] A preferred ink contains at least one pigment. Nearly any pigmentcan be used in the present invention, so long as it can be used in anink jet printer. Preferred pigments include fluorescent pigments,phosphorescent pigments, pearlescent pigments, and conventionalpigments. Pigments can include any colorant permitted in medical devicesand approved by the FDA, such as D&C Blue No. 6, D&C Green No. 6, D&CRed No. 17, D&C Violet No. 2, D&C Yellow No. 10, carbazole violet,certain copper complexes, certain chromium oxides, various iron oxides,phthalocyanine green, titanium dioxides, etc. See Marmiom DM Handbook ofU.S. Colorants for a list of colorants that may be used with the presentinvention.

[0031] The pigment should be much smaller than the orifice in an ink jetnozzle to prevent clogging during the printer process. Generally, thismeans that preferred pigments are 3 microns or smaller. Larger pigmentscan be ground into smaller particles to reduce potential clogging.Preferred methods of reducing a pigment's particle size include highspeed mixers, Kady Mills, colloid mills, homogenizers, microfluidizers,sonalators, ultrasonic mills, ball mills, roller mills, vibrating ballmills, attritors, sand mills, varikinetic dispensers, three-roll mills,Banbury mixers, or other methods well known to those of skill in theart.

[0032] The preferred ink has a surface tension of at least 35 mN/m. Anysurface tension parameter is acceptable so long as the ink jetsadequately spreads when it contacts the lens. Preferably, the ink breaksinto well-defined streams of droplets based upon its surface tension.The surface tension of the ink can be adjusted by adding or removingdiluents or surfactants.

[0033] It is preferred, but not necessary, that the ink dry in less than5 seconds. It is preferred that the ink adhere to the lens and that thelens retain its shape after being treated in an autoclave.

[0034] A preferred ink has organic solvents. Preferred solvents requiresome polarity to dissolve a binder. Preferred solvents have fewfunctional groups that compete with the isocyanate cross-linking systemsuch as alcohol groups, amine groups, and acid groups. A preferred inkcan contain many solvents, including glycols, ketones or esters.Cyclopentanone is a particularly preferred solvent. A preferred inkcould optionally contain humectants (e.g., ethylene glycol) andsurfactants.

[0035] It is also preferred, for continuous ink jet operation, that theink is charged by an electrode to drop away from the gutter and onto theprinting surface. This can be achieved by many ways well known in theart, including by adding about 0.5% by weight of a salt.

[0036] The preferred ink flows easily in ink jet applications.Preferably, the ink has a viscosity of from about 1 centipoise to about50 centipoise. More preferably, the viscosity is from about 2 to about30 centipoise. Most preferably, the viscosity is between 5 and 15centipoise.

[0037] The colorants can be printed in a single layer or in many layers,and in any pattern that achieves desirable cosmetic effects. Preferredpatterns of colorants include those identified in U.S. Pat. Nos.5,936,705; 5,414,477; and 5,272,010, which are hereby incorporated byreference.

[0038] The patterns that the single or multiple layers of colorants formon the contact lenses are preferably comprised of zones, and the zonesmay be comprised of shaped colored regions within the zones. The shapedregion may further be comprised of dots. Examples of zones include: asingle annular iris color zone with irregular inner and outer borders,multiple concentric annular zones, annular zones with outer and innerstarbursts, and a single iris zone but irregular in structure alongmultiple radial lines. Examples of shaped colored areas within zonesinclude circular areas, ovular regions, irregular elongated regions inwormlike shapes, radial segments, and combinations of these shapes

[0039] The addition of surfactants, particularly ionic surfactants, maybe helpful for optimal color dispersion.

[0040] In a preferred embodiment, the colored contact lens is coatedwith a binding solution. Binding can occur during or after printing. Itis preferred that the binding solution be applied to only those regionsof the contact lens that are not in the optical zone, or the zone of thecontact lens through which one sees.

[0041] The process of coating the contact lens can be done by any methodthat is well known in the art. In one embodiment, the binding solutioncould be sprayed onto the lens. If this method is used, a mask should beplaced over the optical zone of the lens before spraying occurs. Inanother embodiment, the binding solution could be coated onto the lensusing printing pads.

[0042] The preferred solvent of the binding solution depends upon themethod of coating used. If the spraying method of coating is used, thesolvent should have a low viscosity. That is, it is preferred that theviscosity be less than 50 centipoise. If the printing pad method ofcoating is used, the solvent should have a higher viscosity. That is, itis preferred that the viscosity be greater than 100 centipoise.Viscosity can be adjusted by the addition or subtraction of polymerchains or by the addition or subtraction of a solvent. Organic mixturesare the preferred solvents.

[0043] Preferably the binding solution comprises at least one monomer.More preferably, the binding solution comprises at least one hydrophilicmonomer and at least one hydrophobic monomer. Nearly any hydrophilicmonomer that can act as a plasticizer can be used. The hydrophilicmonomer can allow the printed material to deform with the lens withoutcracking. Among the preferred hydrophilic monomers are 2-hydroxyethylmethacrylate (HEMA), n-vinylpyrolidone (NVP), glycerylmethacrylate(GMA), and N,N-dimethyacrylamide (DMA). This list is exemplary, notlimiting.

[0044] Nearly any hydrophobic monomer can be used to improve thestrength of the coating and to improve the solubility of the monomer inorganic solvents. Among the preferred hydrophobic monomers are2-ethoxyethyl methacrylate (EOEMA), methyl methacrylate (MMA), andn-butyl methacrylate (BMA). This list is exemplary, not limiting.

[0045] Preferably, the binding solution contains an initiator.Preferably, a UV or heat-activiting initiator is used.

[0046] Preferably, the binding solution makes a tightly cross-linkedfilm that traps the colorants in the film. For this, it is preferable toadd ethylene glycol dimethacrylate. Hexamethylenediisocyanate (HMDI) isanother preferred crosslinker. This list is exemplary, not limiting.Swelling agents are preferably used to allow penetration of the monomerinto the contact lens and they improve adhesion. Preferred swellingagents include cyclopentanone, cyclohexanone, or methyl ethyl ketone.This list is exemplary, not limiting.

[0047] Preferably, the binding solution contains an adhesion promoter.Preferably, the adhesion promoter is HMDI. Nearly any adhesion promotercan be used, including those disclosed in U.S. Pat. No. 5,272,010, whichis incorporated by reference herein.

[0048] Preferably, the binding solution contains a chain transfer agent.Preferably, the chain transfer agent is mercaptoethanol.

[0049] Any ink jet printer can be used with the present invention solong as it can be configured to print the inks as described above oncontact lenses that have curved surfaces. The TRIDENT OPTIJET 2printhead is a preferred printhead available from the Trident Corp. inPark Ridge, Ill.

[0050] A preferred ink jet printer is either drop-on-demand (DOD) orcontinuous-jet. Many continuous ink jet printers could be used, fromcompanies such as Domino-Amjet, Videojet, Scitex Digital Printing,Willet, Linx, Iris Graphics, Stork, and Dupont. Many DOD printers couldbe used, from companies such as Epson, Xaar, Hitachi, Spectra,Tektronix, Canon, Hewlett-Packard, Lexmark, Olivetti, Xerox, Panasonic,VUTEk, and NEC.

[0051] A preferred ink jet printer can print pixels of less than 150microns in diameter, preferably less than 100 microns in diameter. Pixelsize is measured using standard microscopy techniques, which are wellknown to those of skill in the art. A preferred ink jet printer canspace the pixels less than 80 microns from each other, preferably lessthan 50 microns from each other. To achieve this result, it is preferredthat the drops of ink that are emitted from the nozzle have a volume ofless than 100 picoliters, preferably less than 50 picoliters, and morepreferably, less than 10 picoliters.

[0052] A preferred ink jet nozzle is sized to form drops of thepreferred volume given the ink viscosity and thermal forces. Preferably,the nozzles can face perpendicular to the lens surfaces, forming ahemisphere around the lens. Alternatively, the lens surface could berotated. It might also be usful to index the printer head with the lensrotator for non-radially symmetrical lenses with a non-symmetricalpattern.

[0053] In a preferred embodiment, the ink jet heads are controlledthrough the use of a computer.

[0054] In a preferred embodiment, batch processing could be used toprint many contact lenses in rapid succession. For example, a batch ofeight lenses (one palate) could be sent to eight printer heads. Liftspush the lens cup to put it in the vicinity of the printer heads. Thecups could be rotated in a controlled fashion. The print heads would jeton and off based upon instructions sent from the computer software. Thelifts would then lower the lenses back on their palate. Then, the palatewould be sent through a system to print or spray the binding solutionover the lenses. Then, the lenses would be sent to a curing process toheat and dry the lenses.

[0055] Through routine experimentation, one of ordinary skill in the artcan optimize the process of printing colorants onto contact lenses usingvarious quantifiable analytical techniques.

ELECTROPHOTOGRAPHIC PRINTING

[0056] Electrophotographic printing includes laser printing. Referringto FIG. 1, a preferred embodiment is shown. A toner drum 8 transmitstoner to contact lens 6 via a photosensitive metal sphere 9. In thisembodiment, metal sphere 9 rolls over contact lens 6.

[0057] Referring to FIG. 2, a toner drum 18 transmits toner to aphotosensitive metal hemisphere 19. In this embodiment, lens 16 isplaced over the hemisphere 19 after the toner has been printed on thehemisphere 19. The lens 16 is printed on an internal surface.

[0058] Generally, electrophotographic printing works as follows. Acomputer-controlled light source (laser 4 in FIG. 1, laser 14 in FIG. 2)in electrical communication with an RGB (red, green, blue) signal(signal 2 in FIG. 1, signal 12 in FIG. 2) is directed to aphotosensitive drum (drum 8 in FIG. 1, drum 18 in FIG. 2), whichattracts charged toner particles where exposed.

[0059] Print quality is adjusted by varying the charge to attractdifferent concentrations of toner. The toner is then transferred byrolling the contact lens across the drum using rollers.

[0060] For contact lenses, the photosensitive metal sphere 9 orhemisphere 19 could be used instead of the more traditionalphotosensitive drum. Light would be used to charge the sphere 9 orhemisphere 19. Toner particles, one color at a time, would then beexposed to the sphere 9 or hemisphere 19. The sphere 9 or hemisphere 19could then contact a surface of a contact lens 6 or contact lens 16 totransfer the toner to a surface, either external or internal, of thecontact lens 6 or 16.

[0061] Alternatively, the lens could contain a photoconductive monomersuch as vinyl carbazol. This would allow the lens to be placed directlyon the photosensitive hemisphere 19. Light would charge the lens surfacedirectly to allow toner particle transfer without the need for anadditional toner transfer process.

[0062] Compressional forces (via rollers, balls, molds, etc.) could beused to facilitate toner transfer. Adhesive agents such as those thatare well known in the art could be added before or after printing toensure colorfastness.

THERMAL TRANSFER PRINTING

[0063] Referring to FIGS. 3-5, one embodiment of thermal transfer isshown. An RGB signal 22 is in communication with thermal head 24.Thermal head 24 allows heat to pass through a donor ribbon 27, allowingthe color of donor ribbon 27 to pass onto contact lens 26. In thedepicted embodiment, donor ribbon 27 has three sections wherein thefirst section is yellow, the second section is magenta, and the thirdsection is cyan so that only one color is transferred to the contactlens 26 at a time. In another embodiment, there could be one ribbon foreach color that is to be printed. Donor ribbon 27 is supported on spoolsor rollers 23 and 25.

[0064]FIG. 4 is a top view of FIG. 3 taken along line 4-4. FIG. 5 is across section of contact lens 26 taken along line 5-5 after it has beenprinted upon using thermal transfer. Layer 26 is the contact lens, layer31 is yellow, layer 32 is magenta, and layer 33 is cyan. In analternative embodiment, the order in which the color layers are printedonto the contact lens is alternated.

[0065] Thermal transfer technology relies upon the transfer ofimage-forming dyes or colored waxes onto a substrate such as a contactlens 26 or a film for use in a mold where a contact lens is formed. Ananalog image or a digital computer image desired is broken into its RGBconstituents using standard color separation techniques.

[0066] A three-color complement system such as CMY (cyan, magenta, andyellow) can be used as the colorant media to absorb the correspondingcolor (cyan absorbs red, etc.). Each color layer is broken down into araster signal, which controls a thermal head 24 that sequentially passesover a cyan, magenta, and yellow dye or wax donor ribbon 27. Applyingheat causes the donor ribbon 27 to transfer its colorant onto thesubstrate (either contact lens 26 or a film for use in a mold where acontact lens is formed) passing underneath the ribbon 27. After passingover all three sections of ribbon 27, a three-layered surface is formedon the substrate (contact lens) composed of the different colors, asshown in FIG. 5. Process color could be used to form secondary andtertiary colors.

[0067] The ribbon 27 may be flat (typical of printing onto flatsubstrates) and rolled across the surface of the lens using rollers. Apreferred method would use a curved hemispherical-shaped ribbon tofacilitate printing on the hemispherical contact lenses.

PRINTING USING PHOTOGRAPHIC DEVELOPING

[0068] Referring to FIGS. 6 and 7, a digital displayed image 40 isreproduced as an image 44 printed onto contact lens 36. Light burns theimage 40 onto film 35. Film 35 has three light-sensitive layers. Layer37 is blue sensitive, layer 38 is green sensitive, and layer 39 is redsensitive. The contact lens is then chemically treated using filmdeveloping processes well known in the art. Layer 37, which is bluesensitive, forms as much of its complementary color (yellow) as layer 37a as is necessary to reproduce image 40. Likewise, layer 38, whenprocessed, forms its complementary color as layer 38 a, and layer 39forms its complementary color as layer 39 a. Excess material notnecessary for reproduction of the image 40 is either washed away duringchemical treatment or is clear after chemical treatment.

[0069] Photosensitive dyes may be used for digital image capturing,similar to the well-known technology used for photographictransparencies. A film composed of three light-sensitive layers(corresponding to blue, green, and red) is deposited on the contact lenssurface or the surface of a film for use in a mold where a contact lensis formed.

[0070] A computer-controlled light source (such as a cathode-ray tube)is used to expose the color-sensitive layers. The film is thenchemically processed to form the complementary colors to be presented onthe surface being printed upon. The chemical processing or filmdevelopment is done using technology that is well known in the art.

EXEMPLARY USES OF DIGITAL PRINTING

[0071] Digital printing methods and systems of the present invention canfind use in printing on contact lenses cosmetic patterns includingiris-like patterns, WILD EYE™ patterns, made-to-order (MTO) patterns,and the like. Design changes in cosmetic patterns can be implementedeasily, especially across different lens materials and products. Thepattern printed by digital printing methods and systems of the presentinvention can have improved resolution and may be richer in detail.Digital printing methods and systems of the present invention also allowcustomers to design any images or patterns to be printed.

[0072] Digital printing methods and systems of the present invention canalso find use in printing on contact lenses inversion marks. Currently,an inversion mark that allows a user to handle and insert easily acontact lens, for example, a FRESHLOOK™ contact lens (Wesley JessenCorporation). The printed inversion mark is easier to identify and usethan other inversion marks made by non-printing methods includingetching, positively molding, or laser etching. The printed inversionmarks could also provide stronger lenses, since no material is removedand removal of materials from lenses could cause stress propagationsites. In addition, the printed inversion mark may have less adverseimpact on wear comfort, especially with a print-on-mold system.Potentially all contact lens can be printed with an inversion mark. Thedigital printing methods and systems of the present invention can printinversion marks rapidly, potentially faster than pad printing.

[0073] Digital printing methods and systems of the present invention canalso find use in printing on contact lenses stock keeping units (SKUs).Material handling and packaging is always an issue with a large numberof SKUs. The digital printing system may allow SKU codes, either informs of numbers or as bar codes, to be printed either on a mold or insmall print on a contact lens itself. In a preferred embodiment, smallprints of SKU codes is blended in with an iris pattern or any othercosmetic pattern or inversion marks. In another preferred embodiment,SKU codes is printed discretely in black to be hidden by the iris or inwhite to be hidden by the sclera. In a further preferred embodiment, aniris pattern is coded to represent SKUs, for example, two thickstriations followed by two thin striations represents lenses having aprescription of −3.00 D. By printing SKU codes on contact lenses, thedigital printing systems of the invention can aid in monitoring productflow and in verifying product identity in the manufacturing contactlenses. There would be fewer labeling mistakes since every lens could beidentified quickly.

[0074] Digital printing methods and systems of the present invention canfurther find use in printing identity verification marks on contactlenses. By printing an identity code, such as a bar code, number code,special iris pattern, or any other coding system, onto a contact lens,the identity of a contact lens wearer can be verified by reading theidentity code with a simple camera system, preferably the camera systemhaving colored filters. Preferably, the identity codes are printed oncontact lenses with fluorescent or phosphorescent inks. Such a systemcan be used for access to buildings, secure rooms, home security system,ATMs, internet sites, and the like. A potential advantage of using thissystem is that only a person with the correct eye prescription can usethe ID coded contact lens.

SCOPE

[0075] It can be seen that the present invention provides coloredcontact lenses capable of changing the appearance of the wearer's irisand of providing cosmetic effects, inversion marks, SKU codes, andidentity codes. Various changes may be made in the function andarrangement of parts: equivalent means may be substituted for thoseillustrated and described; and certain features may be usedindependently from others without departing from the spirit and scope ofthe invention as defined in the following claims.

1. A method of making a colored contact lens, the method comprisingprinting at least one layer of a colorant onto a contact lens using aprinting process selected from the group consisting of ink jet printing,electrophotographic printing, thermal transfer printing, andphotographic development printing.
 2. The method of claim 1 wherein theprinting process comprises ink jet printing.
 3. The method of claim 2where in the colorant is an ink comprising at least one pigment.
 4. Themethod of claim 2 wherein the colorant is an ink comprising at least onedye.
 5. The method of claim 2 wherein the colorant is an organic-basedink.
 6. The method of claim 2 wherein the colorant is an ink having aviscosity of from about 1 to about 50 centipoise.
 7. The method of claim2 wherein the ink has a viscosity of from about 2 to about 30centipoise.
 8. The method of claim 2 comprising dispersing a firstcolorant into the contact lens before printing.
 9. The method of claim 2further comprising coating the lens with a binding solution.
 10. Themethod of claim 9 wherein the coating is done during printing.
 11. Themethod of claim 9 wherein the coating is done after printing.
 12. Themethod of claim 9 wherein the binding solution comprises at least onemonomer.
 13. The method of claim 9 wherein the binding solutioncomprises at least one hydrophilic monomer and at least one hydrophobicmonomer.
 14. The method of claim 13 wherein the binding solutioncomprises 2-hydroxyethyl methacrylate and 2-ethoxyethyl methacrylate.15. The method of claim 12 wherein the binding solution furthercomprises an adhesion promoter.
 16. A colored contact lens produced bythe process of claim 1 .
 17. The method of claim 1 wherein the printingprocess comprises electrophotographic printing.
 18. The method of claim17 wherein a electrophotographic printer prints the colorant in the formof toner directly onto the contact lens using a photosensitive sphere.19. The method of claim 18 wherein the sphere rolls across the contactlens to transfer toner to the lens.
 20. The method of claim 18 whereinthe lens is placed on the sphere and toner is transferred to the lensusing a toner transfer mechanism.
 21. The method of claim 20 wherein thetoner transfer mechanism is selected from the group consisting of aroller, a mold, and a ball.
 22. The method of claim 17 wherein aelectrophotographic printer prints the colorant in the form of tonerdirectly onto the contact lens using a photosensitive hemisphere. 23.The method of claim 18 wherein the hemisphere contacts the contact lensto transfer toner to the lens.
 24. The method of claim 18 wherein thelens is placed on the hemisphere and toner is transferred to the lensusing a toner transfer mechanism.
 25. The method of claim 20 wherein thetoner transfer mechanism comprises a ball.
 26. The method of claim 1wherein the printing process comprises thermal transfer printing. 27.The method of claim 26 using a multiple-color complement system.
 28. Themethod of claim 27 wherein each component color of the multiple-colorcomplement system is associated with a ribbon for transferring thecomponent color to the contact lens or to a film on a mold for thecontact lens.
 29. The method of claim 28 wherein each ribbon is flat.30. The method of claim 28 wherein each ribbon is curved.
 31. The methodof claim 1 wherein the printing process comprises photographicdevelopment printing.
 32. The method of claim 31 wherein a photographicdevelopment system is used, the system comprising: (a) a film composedof a plurality of light sensitive layers; (b) a computer-controlledsource to expose each of the plurality of light sensitive layers; and(c) a chemical processing system to develop each of the exposed lightsensitive layers, thereby forming a plurality of colors onto the contactlens or onto a film in a mold for the contact lens.
 33. A method ofmaking a colored contact lens, the method comprising: (a) printing afirst layer of a colorant in a first pattern onto a contact lens using aprinting process selected from the group consisting of ink jet printing,electrophotographic printing, thermal transfer printing, andphotographic development printing; (b) printing at least one secondlayer of a colorant in a second pattern onto a contact lens using aprinting process selected from the group consisting of ink jet printing,electrophotographic printing, thermal transfer printing, andphotographic development printing; and (c) coating the colored contactlens with a binding solution comprising a monomer.
 34. A colored contactlens produced by the process of claim 33 .
 35. The method of claim 33wherein step (c) is performed simultaneously with steps (a) and (b). 36.The method of claim 33 wherein the second pattern overlaps the firstpattern, at least in part.
 37. The method of claim 33 wherein the secondpattern overlaps the first pattern such that at least 50% if the firstpattern is covered.
 38. The method of claim 33 wherein the coating isapplied to the contact lens only in regions that are not in an opticalzone.
 39. An improved method of making colored contact lenses, theimprovement comprising printing at least one layer of a colorant onto acontact lens using a printing process selected from the group consistingof ink jet printing, electrophotographic printing, thermal transferprinting, and photographic development printing.
 40. The improved methodof claim 39 wherein the printing step comprises printing onto a film ina mold wherein the film becomes integral with the contact lens when thecontact lens is formed in the mold.
 41. The improved method of claim 39wherein the printing step comprises printing directly onto the contactlens.
 42. The improved method of claim 39 wherein the printing stepcomprises printing onto a pad such that the pad prints directly onto thecontact lens.
 43. A contact lens comprising an image thereon, whereinthe image is selected from the group consisting of a cosmetic pattern,an inversion mark, a SKU code, and an identity code; and wherein theimage is produced using a digital printing process selected from thegroup consisting of ink jet printing, electrophotographic printing,thermal transfer printing, and photographic development printing.
 44. Acontact lens of claim 43 , wherein the image is a cosmetic pattern. 45.A contact lens of claim 44 , wherein said cosmetic pattern is an irispattern.
 46. A contact lens of claim 43 , wherein the image is aninversion mark.
 47. A contact lens of claim 43 , wherein the image is anSKU code.
 48. A contact lens of claim 47 , wherein the contact lensfurther comprises an iris pattern and wherein the SKU code is blendedwith the iris pattern.
 49. A contact lens of claim 43 , wherein theimage is an identity code.